Color photography.



FREDEBIC EUGENE IVES, OF WOODCLIFFE-DN-HUDSON, NEW JERSEY.

COLOR PHOTOGRAPHY.

Specification 0! Letters Patent.

Patented Dec. 29, 1914.

Application filed Augult 5, 1918. Serial No. 718,848.

To all wh om it may concern:

Be it known that I, FREDERIC EUGENE lvns, a citizen of the United States, residing at Vioodclifie-on-Hudson, in the countyof Bergen and State of New Jersey, have invented certain new and useful Improvements in Color Photography, of which the following is a specification.

My invention relates to color 7 photography print-making, and both to the process and the product thereof, as Wlll hereinafter appear.

More particularly my invention relates to the production of multi-color pictures to be viewed by reflected light, as distinguished from mere transparencies or lantern slides.

While satisfactory production of transparencies in a plurality of colors,we will say trichromatic transparencies,has been known for very many years, the production of color-photography pictures to be viewed by reflected light has long presented a problemwhich has not been heretofore satisfactorily met. Transparencies have their own particular field of usefulness, but the popular demand in photographic processes is for prints which may be viewed by reflected light so as to be comparable with ordinary one-color photographs on paper. Reference will now be made to several distinct prior methods that have been proposed and tried for making multi-color prints on paper, none of which, however, it may be said, has proved to have the qualities rendering it satisfactorily available commercially. In this review I will confine myself to the production of multi-color photographs which are composite or built up in their nature, and no reference will be had to contrary methods such as those employing polychromatic screens which form a distinct class with characteristic advantages and disadvantages of their own.

Referring again to transparencies, such for example as made according to my description. published in the Journal of the 'amcm Club, London. April 1894, page 63, it should be stated that in an important sense transparencies are essentially distinct from, and even the contrary of, prints to be viewed by reflected light. In the making of transparencies every effort is directed toward giving them the proper characteristies to yield a perfect blending of colors when held to the light and viewed by transmitted light; this involving certain charac teristics of structure of the individual components of the transparency, and the relative and actual depths of color. A good transparency laid flat upon a piece of white paper Wlll appear so dark and dull and so lacking in visible detail, as to necessitate the positioning of a light at the rear in order to examine the transparency. Thus although transparencies have been known for so many years, their existence per 86 has not afforded the solution ofthe problem of producing satisfactory multi-color prints to be viewed by reflected light. In' the latter the light rays pass first through the colors where they lose much strength, and then strike the white backing where by absorption much further strength is lost, and from the backing the weakened and colored li ht is reflected, again passing through the co or layer with a further loss of strength by both reflection and absorption. This is totally different from the case with transparencies. Indeed in spite of the knowledge of transparencies, those striving after a print on paper have worked along the different lines now to be referred to.

The most common method heretofore attempted for combining the several color prints, has been the stripping method, according to which each of the successive prints would be mounted face down upon the common support and the backing thereupon stripped, after which the same would be done with the next print, and so forth. This stripping method is extremely objectionable owing to the multiplicity and the comparative uncertainty 0 the several operations involved, and owing to the long time required to carry them through to a finished condition. An alternative method hertofore attempted has been that of 81100681 sive sensitizations. After a base print has been made in one color, the same would usually, according to this method, be coated with a water-proof coating and then resensitized, exposed under the second negative, developed, dried, recoated, resensitized, etc. This method. if anything, is more time-consuming than the stripping method and it has never proved satisfactory in practice. In other methods, various expedients were tried. For example, bichromated gelatin films were exposed, washed out to remove the excess or bichromate so as to stop furher action of light, and soaked in a dye so- .lution to such excess that not only the soft,

but even the more hardened parts of the gelatin became saturated, after which upon soaking in clean water, the dye would be removed from the softer parts, having a positive gelatin transparency of uniform thick ness rather than in relief, and which can be superposed upon similar transparencies of other colors, say by the stripping process.

My present invention is distinguished from, and contrary to, the prior methods referied to. It is applicable not only to the three-color system, but to systems involving any other plural number of colors, which is to be understood when hereinafter referring to the three-color system.

I believe that I am the first to produce mi iticolor pictures to be viewed by re flected light, by first making from a proper set of color-selection negatives :1 corresponding set of monochrome positives, all of which positives (vr at least one less than all of which) are dyed colloid reliefs upon transparent carriers, and subsequently superposing in registry all of said positives inclusive of their carriers, there being no stripping. In case one of the positives is on an opaque base, the remainder will. be superposed upon it.

I lay stress in this process not only upon the superposition of the positives with their transparent carriers (6. 9., collodion), but

also that the superposed positives are colloid relief prints, made by exposure from the back of the carrier, Washing away the unaffected colloid (e. g., gelatin) and subsequently dyeing or staining in the proper color. By reason of this I am enabled to properly control the color as it should be;

' I am enabled not only to render the color of the proper lightness of depth (necessary for a print seen by reflected light as distinguished from a transparency), but am enabled to do' so with extreme correctness and delicacy and without weakness or flatness of result. This may be explained in part by the adaptability of such relief prints to be made of exceeding tenuity of relief. In accordance herewith I prefer to render the gelatin reliefs far more tenuous than generally employed reliefs, so much so indeed that the relief will be practically imper- "ceptible, either to the eye or the touch.

With colloid positives of difi'erent charactristic's than specified, correct dyeing to a "light degree would be a difiicult, tedious and at bestuncertain and practically worthless 'process. Uniformity and reliability are peculiarly'essential requirements in color photography. VVitl: the tenuous colloid reliefs specified herein, dyed subsequent to development, the actual differences in relief-as so minute as to practically obviate any nonuniformity or variability in the penetration of the dye. Consequently the relief is capable of being dyed up to the proper lightness of color with all the desired delicacy and correctness.

Advantageous features permitted by this improvement and details of procedure will be new set forth in a complete statement of my preferred process.

Assuming as before stated the three-color system, and having our three color-selection negatives made by sensitization to or selection of the red light rays, the green light rays and the blue light rays respectively from the subject, by exposure for example in a. camera as in my prior Patent No. 632,573 or 980.961, we proceed to the making of the positives. Let it be here stated that the bottommost positive may in some ("uses be a positive on paper (2. g., cyano type print). lVc will assume the three positires shall be the same, and independently provided at the rear with an opaque white backing or sheet of paper.

The transparent carriers for the positives may consist of collodion films, such for can ample as the special collodion referred to in my Patent 960,939, and the colloid coating may consist of gelatin or of fish glue as in said Patent 960,939, or equivalent material, sensitized of course with bichromate or corresponding salt.

In order to render sufiiciently tenuous the final relief, the colloid coating may be treated for that purpose in any known manner, but preferably in the manner set forth in my prior Patent 980,962, namely by incorporating a non-actinic water-soluble dye in the sensitized colloid coating. this serving to restrain penetration of the light, thus reducing the relief and becoming subsequently discharged when developing. I am thus enabled to obtain the extreme tenuity desired and have found that notwithstanding the tenuity the details of the picture are fully preserved as to their gradations of light and shade. By a non-actinic dye, as referred to in said patent, I refer to a dve whose action is to absorb and so limit the penetration of substantially all those light rays to which the bichromated gelatin is sensitive. Such gelatin is not sensitive to the rays at the red end of the spectrum. It is but slightly sensitive to the green, and materially sensitive to the blue and violet, and even the ultra-violet rays. The dye that I prefer to use and whose retarding efiect corresponds substantially with the sensitive ness of the gelatin is of an orange yellow color, such for example as Bavers brilliant yellow. In my said Patent 980.962, lantern slides were produced, and in their production the reliefs were rendered compartively tenuous for the reason that in lantern slides refraction isa serious problem, and it was desired to avo d the necessity of leveling the reliefs with Canada balsam to prevent re fraction. In the present improvement the reliefs are rendered preferably even more tenuous than in Patent 980,962 by an excess of non-actinic dye, for the purposes of securing high quality and attractiveness of prints viewed by reflected light, of avoiding air spaces between the components which will. be substantially non-existent with the extremely low relief, of permitting the correctness and delicacy of dyeing to a light degree as before specified, and incidentally of quickening and simplifying the process. The several prints are then exposed behind the color-selection negatives with the celluloid backs of the prints toward the negatives. After printing the prints will be washed in water suiiiciently warm to dissolve out the unaffected gelatin, the mmactinic dye being dissolved out at the same time. The resulting prints are thin and colorless, no picture being apparent upon them. At this point if desired the prints may be hardened or mordanted, for example in accordance with said'Patent 980,962, by using chromic acid. The prints are next transferred to dye baths of the appropriate complementary colors, for example peacockblue, magenta and yellow respectively. The time of dyeing will be short and this is an advantage of my process. The relief being thin, the dyeing is easily controlled, and controlling agents may be employed in the dye baths if desired in accordance with d-irections already perfected by me. Overdyed prints may be easily and correctly reduced and therefore need not be discarded as would be the case with other types of colloid prints.

As before stated the dyeing is to be of slight degree, producing but a light depth of color. I should judge, for example, that the amount of color absorbed might be substantially in the neighborhood of one-fourth of that in a positive for a transparency or Iantern slide.

Upon drying, the three prints are ready for superposition, a white backing to be provided in either manner before referred to. \Vhen the assembled positives have been placed in proper registry they will be mutually permanently attached, and this I prefer to do by means of a clear cement between the faces of the positives. In this, way is produced a multi-color picture consisting of a single flexible composite sheet which is comparable with an ordinary one-color photograph and fully meets the popular demand. It is obvious that instead of cementing. the positives might be otherwise secured together, but it is one advantage of the present invention that a single flexible composite print is enabled to be produced.

I will now refer to two further and subsidiarv but important features of my preferred process, and so far as the hereinbelow described. features are concerned, they would be applicable to the production of multi-color prints whether viewed by reflected or transmitted light. The first of these features consists in making all (or at least one less than all) of the monochrome positives from reversed negatives, this involving the previous production of reversed negatives w ich may be accomplished in various ways. Since the positives are printed through the back, the use of an unreversed negative will compel the rints to be superposed with the picture si e down- \vardly. I find it, however, desirable that the several positives should have the picture side upwardly, and this is attained by the employment as before stated of reversed negatives. A specific advantageous employment of this improvement is by making one unreversed and, we will say, two reversed negatives, usually the unreversed negative by red li ht and the reversed negatives by green and by blue-violet light respectively. The camera of my Patent 632,573 will produce three such negatives, and my Patent 980,962 may also be employed for that purpose. The present im rovement, indeed, makes an advantage 0 the fact that the cameras constructed under certain principles heretofore disclosed by me will yield both reversed and unreversed negatives. I now prefer to produce from the unreversed negative, a photographic monochrome print upon paper or other white backing; this for example being an ordinary cyanotype or blue-print on paper. The second and third prints I prefer to make as colloid relief prints u on transparent carriers. Being printed mm the back and by means of reversed negatives, the prints will be in correct condition, when placed with the stained side uppermost, to superpose directly upon the underlying paper print. The three prints may be temporarily fastened together at one edge before their final attachment. An additional advantage of this portion of the present invention will now be apparent. When the operator has the three prints superposed and fastened at one edge as above explained, he is enabled to make a careful inspection of the composite picture and to determine to his satisfaction the accuracy or artistic qualities of the result. Frequently it is desirable to modify the color or retouch the print at certain parts, and this is now able to be easily accomplished. Thus the color sides of the three prints all face the operator and so far as any modification of color is found necessary or desirable, color may be as desired readily added to or subtracted from any one or more of the prints, the product of the resulting change bein carefully watched and stopped at any esired point by the application of a blotter or the like. Thus for example, ifa portion of the picture were more red than desired, the operator could either add color to the peacock-blue print or dissolve out a portion of the coloring of the yellow and magenta prints respectively, correspondin to the incorrect area. So far as the relic prints are concerned, their gradation and thickness insures a proper gradation of light and shade whether color be added or removed. The order of superposition of the transparent prints may be altered as desired to permit working upon the different color ima be fore they are finally and permanen y fastened together.

As another subsidiary feature hereof, I prefer to finally cement together the three monochromes in the novel manner to be now described.

The three prints being fastened together along one edge are opened out like the leaves of a book and while open a sufiicient quantity of liquid balsam or other transparent cement is poured into the bottom of both of the V-shaped grooves thus produced. The prints are then closed together again and preferably laid between two sheets of soft blotting paper, whereupon presure will be applied to cause the cement to spread from the fastened edges of the prints and cover the entire area thereof. Rather than do this merely by hand pressure or a squeegee roll, I prefer to insert the combined prints and blotters in a suitable covering such as a. paper bag and then run them between a pair of compression rolls constituted, for example,'of rubber or other elastic material, with the fastened edges of the prints foremost. On turning the rolls the prints will be drawn through and forcibly pressed together, at the same time spreading the cement uniformly and entirely over the adjoining surfaces of the three prints. Any surplus cement will be expressed from between the prints and absorbed by the blotters so that the cemented composite print may be safely removed without risk of any of the cement becoming ap lied to the outside surfaces.

y the improvement just described, what would ordinarily be a troublesomeand messy prom of fastening the prints together. is enabled to be accomplished with celerity, cleanliness and precision, and without the exercise of any special skill.

Manifestly the cementing described might be done with a liquid such as Canada balsam, but as that material will not dry out between the impervious films, the films will not become permanently attached but will be liable to partial separation if subjected to fiexure or if buckled by the action of heat. I therefore preferably employ a cement of amyl-acetate collodion containing a 1 amount of camphor, and with the we 0 this the amyl-acetate attacks the surface of the celluloid or collodion, of which the supporting films are composed, to a sufficient degree to hold them firmly and permanently together; while at the same time too much softening of the film is avoided by using such heavy roller pressure in the cementing operation, and with such promptness as to expel all but a sufficient though small quantity of the amyl-acetate collodion liquid to insure a firm connection. The presence of a considerable amount of dissolved cam hor also favors the reservetion of the integrity of the celluloid or collodion films. The small amount of amylacetate and camphor retained becomes diffused into the substance of the film without either dissolving or disintegratin it but leav ng it firmly attached and fiexi le.

SlIlc8 certain of the described matters are capable of illustration, drawings are appended hereto, in which, for convenience, th1n dimensions are exaggerated.

Figure 1 shows a partial section of one of the positives. Fig. 2 shows three of the positives, color side uppermost, with a paper back, the four being unattached but in proper relative position. Fig. 3 shows the same components as in Fig. 2, but permanently cemented together. Fig. 4 shows the same photograph of Fig. 3, but without exaggeration, and illustrating the flexibility which is attainable. Fig. 5 illustrates the temporary attachment at one edge of three positives, the underneath one consisting of a cyanotype on paper. Fig. 6 illustrates the spreading of cement between the faces ponents at one edge, they may be cut to overlap, as shown in Fig. 5, and an adhesive strip 20 pasted over the edges.

For cementin the positives can be opened, as in Fig. 5, like the leaves of a book, and a quantity of transparent cement introduced at the bottoms of the two grooves. Fig. 6 shows the cement 21 being forced forwardly to spread it between the faces of the positives. Before this the assembled positives are placed between the absorbent blotters 22, 22, which may be placed in a paper bag 23 and the whole then passed between elastic rollers 24, 25, under high pressure.

Since it is obvious that the several features hereof might be variously modified without departing from the general rinciples involved, I do not wish to be limited to details of process excepting as specified in the appended claims.

The product or print produced by following the process above described, need not be further referred to as it has been incidentally disclosed in the above description. Such a print has not only the advantages of an opaque or fpaper backing, and of the best disposition o the component color images, but possesses other advantages that will be well understood by those familiar .with the art.

What I claim and desire to secure by Letters Patent is:

1. In the art of color photography, the method of making from a set of color-selection negatives a multi-color print having a suitable base adapting it to be viewed by reflected light, such method comprising the following steps: firstly, preparing from such color-selection negatives one or more separate transparent monochrome positives of the appropriate different colors, each roduced by (a) exposing from its rear and beneath one of such color-selection negatives a sensitive colloid layer backed by a transparent carrier, (b) then developing the same to attain a positive relief, and (c) subsequently coloring such positive relief to a slight depth of the appropriate color, thereby securing such transparent monochrome positive; and finally, bodily superposing and securing together in registry the several transparent positives with their carriers and with a suitable reflecting base beneath.

2. In the art of color photography the method of making from a set of color-selection negatives a multi-color print having a paper or analogous reflecting base adapting it to be viewed by reflected light, such method comprisin the following steps: firstly, preparing rom such color-selection negatives a set of separate monochrome positives of the appropriate different colors, each of which above the reflecting base is a transparent positive prepared by, (a) exposing from its rear, and beneath one of such color-selection negatives, a sensitive colloid layer backed by a transparent carrier, (b) then developing the same to attain a colorless positive relief, and (a) subsequently dyeing such positive relief to a slight depth of the appropriate color, thereby securing such transparent monochrome positive; and secondly, bodily su perposing and securin together in registry the transparent positives with their carriers and with a suitable reflecting base beneath, which base may or may not be the bottommost positive.

3. In the art of color photography the method of making from a set of color-selection negatives a. multi-color print having a. paper or analogous reflecting base adaptm it to be viewed by reflected light, sucl method comprisin the following steps: firstly, preparing romsuch color-selection negatives a set of separate monochrome positives of the appropriate different colors, each of which above the reflecting base is a transparent positive prepared by, (a) exposing from its rear, and beneath one of such color-selection negatives, a sensitive colloid layer backed by a strong thin tenacious transparent carrier, (1)) then developing the same by dissolving out the unaffected colloid to attain a colorless positive relief, and (a) subsequently dyeing such positive relief with a water soluble dye to a slight depth of the appropriate color, thereby securing suchtransparent monochrome positive; and secondly, bodily superposing and securing together in registry the transparent positives with their carriers and with a suitable reflecting base beneath, which base may or may not be the bottommost positlve.

4. In the art of color photography the method of making from a set of color-selection negatives a lnulti-color print having a paper or analogous reflecting base adapting it to be viewed by reflected light, such method comprisin the following steps: firstly, preparing rom such color-selection negatives a set of separate monochrome positives of the appropriate different colors, each of which above the reflecting base is a transparent positive prepared by, (a) exposing from its rear, and beneath one of such color-selection negatives, a sensitive colloid layer backed by a transparent carrier, and restraining the penetration of light during such exposure by a soluble temporary non-actinic dye incorporated in the colloid, (b) then developing the same to at tain a colorless positive relief, and (0) subsequently dyeing such positive relief to a slight depth of the appropriate color, thereby securing such transparent monochrome positive; and secondly, bodily superposing and securing together in registry the transparent positives with their carriers and with a suitable reflecting base beneath, which base may or may not be the bottommost positive.

5. In the art of color photography the method of making from a set of color-selection negatives a multi-color print having a paper or analogous reflecting base adapting it to be viewed by reflected light, such method comprising the following steps: firstly, preparing from such color'seleetion negatives a set of separate monochrome positives of the appropriate different colors, each of which above the reflecting base is a transparent positive prepared by, (0.) exposing from its rear, and beneath one of such color-selection negatives, a sensitive colloid layer backed by a transparent carrier, (b) then developing the same to attain a colorless positive relief, and (0) subsequently dyeing such positive relief to a slight depth of the appropriate -color, thereby securing such transparent monochrome positive; an secondly, bodily superposin in registry the transparent positives with t eir carriers and with a suitable reflecting base beneath, which base may or may not be the bottommost positive; and thirdly, attaching the whole together into a single composite flexible opaque-backed sheet, by a colorless cement, as amyiacetate collodion.

6. In the art of color photography the method of making from a set of color-selection negatives a multi-color print having a paper or analogous reflecting base adapting it to be viewed by reflected light, such method comprising the following steps: firstly, preparing from one of such colorselection negatives a monochrome of one color on an opaque base, as a cyanotype on paper, to form the bottonmost positive, and from the other negative transparent monochrome positives of the other color, each such trans arent positive prepared by, (a) exposing rom its rear, and beneath one of such color-selection negatives, a sensitive colloid layer backed by a transparent carrier, (6) then developing the same to attain a colorless positive relief, and (c) subsequently dyeing such positive relief to a slight depth of the appropriate color, thereby securing such transparent monochrome positive; and secondly, bodily superposing and securin together in registry the transparent positives with their carriers and with said opaque positive beneath.

7. In the art of color photography the method of making a multi-color print from two or more color-selection negatives, consisting in preparing a suitable monochrome positive from one of said no atives, preparing colloid relief positives rom the remainder thereof, superposing in registry the last named upon the first positive, and tem porarily fastening the superposed positives along one edge, followed by opening out the attached positives, providing colorless cement in the V-groove between them, and the finally closing the same and applying pressure to spread the cement toward the opposite edge and cause permanent adhesion.

8. As an improvement in the production of a colored composite photographic picture comprising a basic print and one or more superposed dyed transparent, colloid relief prints, the mode herein described of secur- 1ng said prints together, said mode consisting in first securing the prints at one edge, introducing between the prints at such secured edge a su ply of transparent cementing material, 0 osing the prints upon one another, placin them between sheets of absorbent materia and passing the latter, and the prints between them, between a air of compression rolls in such direction t at the connected edges of the prints will first enter between the rolls.

9. A color-photogra hy print-making process comprising pro ucing two or more color-selection negatives, making a mono chrome positive from one of said negatives, making colloid reliefs on transparent carriers from the remainder thereof, staining such reliefs of the appropriate colors, superposing in registry the last named upon the first positive, temporarily fastening them along one edge for examination, eifecting desired replacement or color modification, and finally permanently attaching all the positives together with their carriers.

10. In the art of color photography the method of making from a set of colorselection negatives a multi-color print havmg a paper or analogous reflecting base adapting it to be viewed by reflected light, such method comprising the following steps: firstly, preparing from such colorselection negatives a. set of separate monochrome positives of the appropriate different colors, each of which above the reflectmg base is a transparent positive prepared from a reversed negative by, (a) exposing from ts rear, and beneath one of such colorselection negatives, a sensitive colloid layer backed by a transparent carrier, (6) then developing the same to attain a colorless positive relief, and (c) subsequently dyeing such positive relief to a slight depth of the appropriate color, thereby securing such transparent monochrome positive; and secondly, bodily superposing and securing together in registry relief side outward the transparent positives with their carriers and with a suitable reflecting base beneath, which base may or may not be the bottommost positive.

11. In the art of color photography the method of making from a set of color-selection negatives a multi-color print having a paper or analogous reflecting base adapting it to be viewed by reflected light, such method comprising the following steps: firstly, preparing from an unreversed negative a monochrome of one color on an opaque base, as a cyanotype on paper, to form the bottommost positive, and from reversed negatives transparent monochrome positives of the other colors, each such transparent positive prepared by, (a) exposing from its rear a sensitive colloid layer backed by a transparent carrier, (5) then developing the same to attain a colorless positive relief, and (c) subsequently dyeing such positive relief to a slight depth of the appropriate color, thereby securing such transparent monochrome positive; and secondly, bodily superposing and securing together in registry the transparent positives with their carriers and with said opaque positive beneath, and with all the positives facing color side outward.

12. In the art of color photography the method of making from a set of color-selection negatives a multi-color print having a paper or analogous reflecting base adapting it to be viewed by reflected light, such method comprisin the following steps: firstly, preparing from such color-selection negatives a set of separate monochrome positives of the appropriate different colors, each of which above the reflecting base is a transparent positive prepared from a reversed negative by, (a) exposing from its rear, and beneath one of such color-selection negatives, a sensitive colloid layer backed by a transparent carrier, (b) then developing the same to attain a colorless positive relief, and (c) subsequently dyeing such positive relief to a slight depth of the appropriate color. thereby securing such transparent monochrome positive; and secondly, bodily superposing in registry relief side outward the transparent positives with their carriers and with a suitable reflecting base beneath, which base may or may not be the bottommost positive; thereafter temporarily fastening the registered positives, modifying the coloring under inspection as desired, and finally permanently attaching the whole together.

13. In the art of color photography the method of making from a set of color-selection negatives a multi-eolor print havin a paper or analogous reflecting base adapting it to be viewed by reflected light, such method comprising the following steps: firstly, preparing from an unreversed negative a monochrome of one color on an opaque base, as a cyanotype on paper, to form the bottommost positive, and from reversed negatives transparent monochrome positives of the other colors, each such transparent positive prepared by, (a) exposing from its rear a sensitive colloid layer backed by a transparent carrier, (b) then developing the same to attain a colorless positive relief, and (c) subsequently dyeing such positive relief to a slight depth of the appropriate color, thereby securing such transparent monochrome positive; and secondly, bodily superposing in registry the transparent positives with their carriers and with said opaque positive beneath, and with all the positives facin color side outward; thereafter temporarily fastening the registered positives, modifying the coloring under inspection as desired, and finally permanently attaching the whole together.

14, A color-photography print made from a set of color-selection negatives and comprisin a suitable paper or analogous reflecting ase, in-combination with separately prepared transparent monochrome positives; each such positive consisting of a colloid relief borne on its own thin transparent carrier and stained to a sli ht depth of the appropriate color; and afi permanently attached to other in regist 15. A color-p otography print made from a set of color-selection negatives and comprising a suitable paper or analogous reflecting base, in combination with separately prepared transparent monochrome positives; each such positive consisting of a colloidal relief borne on its own thin transparent carrier and stained by a water solule dye to a sli ht depth of the appropriate color; and a1 permanently attached together in re istry.

16. A co or-photography print made from a set of color-selection negatives and comprising a suitable paper or analogous reflecting base, in combination with separately prepared transparent monochrome positives; each such positive consisting of a colloid relief borne on its own thin trans parent carrier and stained to a slight depth of the appropriate color; and all permanently attached together in registry, with the topmost positive facing colored relief side outward.

17. A color-photography print made from a set of color-selection negatives and comprising a suitable paper or analogous reflecting base, in combination with separately prepared transparent monochrome positives; each such positive consisting of a colloid relief borne on its own thin transparent carrier and stained to a slight depth of the appropriate color; and all permanently attached together in registry and all face outward.

18. A flexible color-photography print made from a set of colorseleetion negatives and com rising a suitable paper or analogous re eeting base, in combination with separately prepared transparent monochrome positives; each such positive consisting of a colloid relief borne on its own thin transparent flexible carrier and stained to a slight depth of the appropriate color: and all permanently flexibly at tached together in registry by colorless cement between the positives.

19. In the art of color photography, the method of making from a set of color-selection negatives a multi-color print having a suitable base adapting it to be viewed by reflected light, such method comprising the following steps: firstly, preparing from such color-selection negatives a plurality of separate transparent monochrome positives of the appropriate different colors, by (a) exposing from the rear and beneath such color-selection negatives a plurality of sensitive colloid layers all havin the same-degree of actinic-light retardation and backed by a clear transparent carrier, (b) and then developing the exposed members to attain positive reliefs and coloring them to a suitable dc th of the appropriate colors; and finally, odily superposing and securing together in registry the several transparent monochrome positives with their carriers and with a suitable reflecting base beneath.

20. In the art of color photography, the method of making from a set of color-selection negatives a multi-color print having a suitable base adapting it to be viewed by reiiccted light, such method comprising the following steps: firstly, preparing from such color-selection negatives a plurality of separate transparent monochrome positives of the appropriate different colors, by (B) exposing from the rear and beneath such color-selection negatives a plurality of sensitive colloid layers all having the same degree of actinic-light retardation and backed by a clear transparent carrier, (b) and then developing the exposed members to attain positive reliefs and dyeing them to a suit- FREDERIC EUGENE IVES.

Witnesses DONALD CAMPBELL, ELIZABETH B. Juno.

It is hereby certified that in Letters Patent No. 1,122,935, granted December 29, 1914, upon the application of Frederic Eugene Ives, of Woodclifl'e-on-Hudson, New Jersey, for an improvement in Color Photography, errors appear in the printed specification requiring correction as follows: Page 2, line 4, for the word having read leaving, same page, line 61, for the word as read are; page 6, line 26, for the word bottonmost read bottommost; same page, line 27, for the word negative read negatives; same page, line 29, for the word color read colors," page 7, line 81, for the word colloidal read colloid; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 9th day of March, A. D., 1915.

J. T, NEWTON,

.Acting Commissioner of Patanta.

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